1. Field of the Invention
The present invention relates generally to a prosthodontic method of repairing one or more teeth in a patient's mouth and, more particularly, to a miniature detachable fastener which is located within the confines of an artificial crown and a coping. The fastener is installed within each tooth to be repaired pursuant to such method.
2. Description of the Prior Art
In the art of dental prosthesis, it is known to prepare a tooth in need of major prosthodontic repair and then to cement an artificial crown or cap on the prepared tooth. A prepared tooth is one which has some or all of its structure removed. Conventionally, the side walls of such prepared teeth are tapered upwardly for a lower tooth and downwardly for an upper tooth such that such teeth have a generally frusto-conical configuration. This configuration facilitates the secure mounting of a coping over the prepared tooth, as well as the mounting of the cap over the coping.
The permanent attachment of a cap either directly on the tooth or on the coping is highly unsatisfactory because once the cap is permanently emplaced, it is not easy to replace it in order to modify or correct an occlusion. Such permanent emplacement also makes it very difficult to remove the cap without causing damage to the cap and/or the tooth and/or the surrounding gingival tissue. Moreover, it is very difficult to thoroughly clean and maintain this gingival tissue healthy.
In another type of dental prosthesis, it is known to prepare teeth at the ends of a gap caused by extraction of one or more teeth. These prepared end teeth serve as anchors for two caps provided at opposite ends of a bridge structure. A plurality of artificial teeth are interconnected to the two caps. The permanent emplacement of such a bridge structure not only has the drawbacks noted above for the capping of a single tooth, but also permits food particles to enter into the space between the bottoms of the intermediate artificial teeth and the gums. Such food particles are difficult to remove, facilitate the formation of diseased tissue and cause foul odors to form. Massaging and cleaning of the gum tissues likewise become more elaborate.
It is further known in the art to make removable caps and removable bridges. It has been proposed to form a vertical dovetail mortise in a tooth adjacent a gap and to mount a vertical dovetail tenon on a single artificial tooth which then would be held in the gap by a mortise-and-tenon connection. It has been further proposed to provide metal clips or clasps which engage the external surfaces of the patient's teeth adjacent the ends of the gap to be closed by a bridge. Such metal clasps are subject to material fatigue and also place an undue stress upon the engaged teeth.
It is known in U.S. Pat. No. 3,797,114 to mount a two-part detachable fastener partly within the confines of a cap and partly within the confines of a coping which is attached to a prepared tooth. Such detachable fasteners generally overcome the drawbacks noted above; however, they have not proven to be altogether satisfactory in use due to improper alignment of the two parts of the fasteners. Such fasteners are generally of large dimensions and therefore are not well adapted to be easily fitted within the confines of small prepared teeth.
Another prior art proposal for a detachable fastener requires the root of the tooth to be repaired to be as short as possible in order to mount the fastener. In other words, all of the structure of the tooth is removed down to the gingival margin, and even below the same; that is, the entire upper portion of the tooth is ground off leaving only the root embedded in the gums and jawbone. This is very disadvantageous because it constitutes a very radical procedure which tends to shock the patient's physiological system. It will be appreciated that the root of a tooth is considerably more slender than the portion of the tooth above the gingival margin, and that the hard skin of a root is not as thick or as hard as the enamel of a patient's crown. Therefore, when this prior art fastener is mechanically integrated with a patient's tooth, a considerable danger exists for fracture in the root during such mounting and/or during the preparation of the tooth. In extreme cases, once this root is damaged, the dentist must extract the tooth, frequently with considerable suffering to the patient. The dentist must now proceed with securing the fastening means to the jawbone itself. However, this procedure imparts an even greater physiological shock to the patient's system. If the jawbone structure is weak, immeasurable damage occurs.